What does the Apolipoprotein A1 test measure?

Why is Apolipoprotein A1 measured?

Apo A1 concentration reflects the number of circulating HDL particles and is a marker of reverse cholesterol transport capacity. Low Apo A1 predicts increased cardiovascular risk independently of HDL-cholesterol, particularly in settings where HDL-cholesterol and particle number diverge — such as hypertriglyceridaemia or metabolic syndrome. Apo A1 is also used to calculate the ApoB:ApoA1 ratio, a lipoprotein balance metric that can outperform traditional lipid ratios in risk stratification.

Reference ranges

Standard reference

Approximately 94–178 mg/dL; varies by sex, age, and laboratory.

Functional medicine optimal

Cardiovascular epidemiology suggests that Apo A1 >120 mg/dL in women and >130 mg/dL in men confers lower risk, though optimal targets depend on the individual's global cardiovascular profile and are not universally standardised.

Units

mg/dL, g/L

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.